In a preview clip for an upcoming interview with Larry King for Larry King Now, Warwick speaks out against the accusations.

“I have tried to refrain from responding to that. First of all, it’s totally hogwash,” Warwick said. “My sister would never, ever have done anything to do any harm to any child, especially within our family. And for those lies to be perpetuated in this so-called documentary film, I think it’s evil.”

Last month, Houston’s mother Cissy Houston also denied allegations made in the documentary and blasted the filmmakers for waiting until two days before the film’s premiere to reveal the molestation claims would be included.

In the Larry King Now interview, Warwick added, “I will never, and I mean this, ever forgive those who perpetuated this insanity.”

In Whitney, the “I Will Always Love You” singer’s longtime assistant Mary Jones reveals that Houston told her she had been molested as a child by her cousin Dee Dee Warwick. Houston’s brother Gary also reveals in the film that a female family member molested him from the ages of 7 to 9 when his mother Cissy would leave him and his siblings with relatives while she toured.